Tube-adjusting device

ABSTRACT

A tube-adjusting device includes a tubular guide having a longitudinal line of apertures and a longitudinal groove diametrically opposite to the line of apertures. A tube extends in the tubular guide and has an inner transverse column defining a through-hole aligned with alternative one of the apertures and with the longitudinal groove of the guide. The inner transverse column has a threaded inner wall adjacent to the longitudinal groove. A pin is movable in the through-hole of the inner transverse column, and has a rounded end adapted to engage the apertures of the guide. A thumbscrew has a threaded shank extending into the through-hole in the transverse column through the longitudinal groove, and is threadedly engaged with the threaded inner wall. Additionally, a helical spring is received in the through-hole of the inner transverse column and compressed between the pin and the threaded shank of the thumbscrew.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a tube-adjusting device and, more particularly, to a tube-adjusting device in which a tube suffers no local permanent deformation in its wall and is positioned securely after adjustment.

[0003] 2. Description of Related Art

[0004] Many exercising apparatus, such as stationary exercising bicycles, have seats that are adjustable relative to main bodies. The adjustment is usually achieved by means of a tube-adjusting device, which includes a tubular guide formed on the main body and a seat tube extending into the tubular guide. In any device of the conventional types, the tube is locked with the tubular guide by a thumbscrew that is threadedly connected to the guide and pressed against a wall of the seat tube.

[0005] The tube, however, is vulnerable to the pressure from the thumbscrew, being usually subjected to local permanent deformation, which causes a negative effect to the smooth movement of the tube in the tubular guide during adjustment.

[0006] A more serious problem is that the tube is locked with the guide solely by the friction between the tube and the thumbscrew. The unreliable friction may result in the user's fall from the seat if the tube is unlocked suddenly and intendedly, thereby leading to possible injury.

[0007] Therefore, it is an objective of the invention to provide a tube-adjusting device to mitigate and/or obviate the aforementioned problems.

SUMMARY OF THE INVENTION

[0008] The object of the present invention is to provide a tube-adjusting device in which a tube suffers no local permanent deformation in its wall.

[0009] Another object of the present invention is to provide a tube-adjusting device in which a tube is positioned securely after adjustment.

[0010] Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a fragmentary exploded perspective view of a tube-adjusting device in accordance with the present;

[0012]FIG. 2 is a fragmentary perspective view showing the device of FIG. 1 in assembly;

[0013]FIG. 3 is a fragmentary cross-sectional view showing a tube in a locked position;

[0014]FIG. 4 is a fragmentary cross-sectional view showing the tube in an unlocked position; and

[0015]FIG. 5 is a view of a stationary exercising bicycle provided with the tube-adjusting device shown in FIGS. 1 to 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0016] Referring to FIGS. 1 and 2, a tube-adjusting device in accordance with the present invention includes a tubular guide (30) having at least one open end (31), with a tube (40) extending partially in the tubular guide (30) through the open end (31).

[0017] The tubular guide (30) includes a longitudinal line of apertures (34), such as defined in an additional plate (33) fixed to the guide (30) in a manner as illustrated, and a longitudinal groove (35) substantially parallel to and diametrically opposite to the longitudinal line of the apertures (34).

[0018] Preferably, the tubular guide (30) has a pair of longitudinal slots (36) defined at sides of the groove (35), while the tube (40) is formed with a pair of wheels (45) rotatable along the longitudinal slots (36), as best shown in FIG. 2. More preferably, the tubular guide (30) further has a secondary wheel (32) formed adjacent to its open end (31) to support the tube (40), thereby providing a smooth movement for the tube (40) relative to the guide (30).

[0019] The tube (40) is formed with an inner transverse column (42) that defines a through-hole (43) in alignment both with alternative one of the apertures (34) and with the longitudinal groove (35) of the guide (30). In addition, the inner transverse column (42) has a threaded inner wall (431) adjacent to the longitudinal groove (35) for defining a portion of the through-hole (43), as best seen in FIG. 1.

[0020] A pin (20) is movable in the through-hole (43) of the inner transverse column (42). The pin (20) has a rounded end (23) adapted to engage with alternative one of the apertures (34) of the guide (30), and preferably a reduced upper end (21) that allows a helical spring (24) to be received in the through-hole (43) of the inner transverse column (42) and mounted at least partially around the pin (20) at the reduced end (21), abutting a shoulder (22) of the pin (20), as best shown in FIG. 3.

[0021] Referring to FIG. 3, the inventive device further includes a thumbscrew (10) having a knob (11), with a threaded shank (12) extending from the knob (11) into the through-hole (43) in the inner transverse column (42) of the tube (40), through the longitudinal groove (35) of the tubular guide (30). The threaded shank (12) is threadedly engaged with the threaded inner wall (431) of the inner transverse column (42), thereby compressing the helical spring (24) between the pin (20) and the shank (12).

[0022] The tube (40) can be locked with the tubular guide (30) by turning the thumbscrew (10) in a direction until its threaded shank (12) is pressed tightly against the pin (20), when the rounded end (23) is urged to project in desired one of the apertures (34), thereby retaining the tube (40) in place in the guide (30).

[0023] Referring to FIG. 4, the tube (40) can be released by turning the thumbscrew (10) in the opposite direction. At this time, the threaded shank (12) is moved away from the pin (20), and the rounded end (23) may slide out one aperture (34) and then into another, under the action of the compressed spring (24), as the tube (40) is moved along the tubular guide (30). This allows the tube (40) to be adjusted relative to the guide (30).

[0024] Referring to FIG. 5, there is shown a stationary exercising bicycle provided with the tube-adjusting device in accordance with the present invention. The stationary bicycle here includes legs (50) supporting a pedal unit (52), with the tubular guide (30) extending from the unit (52). A seat (55) is formed with a base (551) attached to the tube (40), which, as mentioned above, extends into the tubular guide (30) through its open end (31).

[0025] With the inventive device, the seat (55) can be adjusted easily in the manner as described with reference to FIGS. 3 and 4.

[0026] From the above description, it is noted that the invention has the following advantages:

[0027] 1. No Local Permanent Deformation of the Tube (40):

[0028] Because the threaded shank (12) of thumbscrew (10) is pressed against the pin (20) instead of the tube (40) itself, the tube (40) will suffer no local permanent deformation from the thumbscrew (10).

[0029] 2. Ideal Security in Positioning the Tube (40) After Adjustment:

[0030] Because the tube (40) is locked with the tubular guide (30) by the pin (20) instead of unreliable friction, the tube (40) and hence the seat (55) will be positioned securely after adjustment.

[0031] It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

What is claimed is:
 1. A tube-adjusting device comprising: a tubular guide (30) having at least one open end (31), said guide (30) being formed with a longitudinal line of apertures (34) and a longitudinal groove (35) substantially parallel to and diametrically opposite to said longitudinal line of said apertures (34); a tube (40) extending partially in said tubular guide (30) through said open end (31), said tube (40) having an inner transverse column (42) defining a through-hole (43) in alignment with alternative one of said apertures (34) and with said longitudinal groove (35) of said guide (30), said inner transverse column (42) having a threaded inner wall (431) adjacent to said longitudinal groove (35) for defining a portion of said through-hole (43); a pin (20) movable in said through-hole (43) of said inner transverse column (42), said pin (20) having a rounded end (23) adapted to engage with alternative one of said apertures (34) of said guide (30); a thumbscrew (10) having a threaded shank (12) extending into said through-hole (43) in said inner transverse column (42) of said tube (40) through said longitudinal groove (35) of said tubular guide (30), said threaded shank (12) being threadedly engaged with said threaded inner wall (431) of said inner transverse column (42); and a helical spring (24) received in said through-hole (43) of said inner transverse column (42) and compressed between said pin (20) and said threaded shank (12) of said thumbscrew (10).
 2. The tube-adjusting device as claimed in claim 1, wherein said thumbscrew (10) has a knob (11) from which said threaded shank (12) extends.
 3. The tube-adjusting device as claimed in claim 2, wherein said pin (20) has a reduced end (21) opposed to said rounded end (23), and wherein said helical spring (24) is mounted at least partially around said pin (20) at said reduced end (21).
 4. The tube-adjusting device as claimed in claim 3, wherein said tubular guide (30) has a pair of longitudinal slots (36) defined at sides of said longitudinal groove (35), and wherein said tube (40) is formed with a pair of wheels (45) rotatable along said longitudinal slots (36) of said guide (30).
 5. The tube-adjusting device as claimed in claim 4, wherein said tubular guide (30) further has a secondary wheel (32) formed adjacent to said open end (31) to support said tube (40). 